Kneading or mixing device



April 23, 1935. w. J. VAN ROSSEM -r AL; 1,998,692

KNEADIVNGY OR MIXING DEVICE Filed Oct. 10, 1933 2 Sheets-Sheet 1 April1935. w. J. VAN ROSSEM ET AL 1,998,692

KNEADING OR MIXING DEVICE Fil ed Oct. 10, 1933 2 Sheets-Sheet 2 PatentedApr. 23, 1935 UNITED STATES KNEADING OR DEVICE Walter J. van Rossem, LosAngeles, and Laurence E. Harrison, Eagle Rock, Calif., assignors toOramold Products Corporation, Los Angeles,

Calif., a corporation of Nevada Application October 10 14 Claims.

This invention relates to an apparatus for kneading or mixing substancesheld in a container. While the apparatus may be used to per-'- form thisfunction in different arts, the device is 5 intended to be particularlyuseful for dentists in mixing or kneading compositions useful inperforming dental work.

The apparatus includes a container preferably in the form of a cylinderor barrel in which the substance to be kneaded is placed. A piston ismovably mounted in the cylinder to travel to and fro, and this pistonhead is provided with perforations through which the substance passes asthe piston advances. After the kneading operation has been completed,the piston operates to expel the substance from the cylinder orcontainer.

The general object of this invention is to improve the generalconstruction of devices of this kind and particularly to provide simplemeans for controlling the perforations so that they may remain open whenusing the piston to knead the substance in the cylinder and so that theycan be closed thereafter to facilitate the expulsion of the substancefrom the cylinder.

One of the objects of the invention is to provide an assembly of partswhich can be readily taken apart for cleaning and sterilization. In itsconstruction the device includes a piston rod carrying the piston. Oneof the objects of the invention is to provide a simple construction forthe device which will enable the rod to be constructed of a single pieceand to provide means cooperating with the rod so that at will theperforations can be closed or maintained open.

A further object of the invention is to produce 'a device of this kindin which the piston rod includes an inner rod and an outer tubular rod,and to provide simple means to cooperate with such-a rod to enable theperforations to be maintained opened or closed at will.

A further object of the invention is to provide a device of this kindwith simple means for controlling the perforations'from the exterior,and for indicating on the exterior of the device, the relation of theperforations, that is to say, for indicating whether the perforationsare opened or closed.

A further object of the invention is to produce a device of this kindhaving a single handle for reciprocating the piston.

Further objects of the invention will appear 'hereinafter. i

The invention consists in the novel parts and combination of parts to bedescribed hereinafter,

, 1933, Serial No. 692,936

(Cl. 2591ll3) all of which contribute to produce an efiicient kneadingor mixing device.

A preferred embodiment of the invention is described in the followingspecification, while the broad scope of the invention is pointed out inthe appended claims.

In the drawings:

Fig. 1 is a vertical section through a. complete kneading deviceembodying our invention and illustrating the same with the perforationsin their open position;

Fig. 2 is a vertical section taken about on the line 2-2 of Fig. 1 withcertain parts broken away, and particularly illustrating the means forholding parts of the piston so that the perforations through the pistonwill be in a definite relation, that is to say, opened or closed.

Fig. 3 is a horizontal cross section taken on the line 33 of Fig. l andfurther illustrating details of the device.

Fig. 4 is a vertical section taken through the upper head of the deviceand illustrating another embodiment of the invention, in which we employmarks on the piston rod and head of the barrel to indicate the relationor condition of the perforations. In this view the upper portion of thepiston rod is broken away and the piston head is illustrated in crosssection.

Fig. 5 is a section through the piston rod taken on the line 5-5 of Fig.4 showing the upper head of the device inplan and illustrating the useof marks on the exterior of this head for enabling the condition of theperforations through the piston to be controlled.

Fig. 6 is a view similar to Fig. 4 but illustrating another embodimentof the invention which dispenses with the use of. marks for indicatingthe condition of the perforations, and which provides means whereby theparts of the piston can be readily controlled to maintain theperforations opened or closed at will.

Fig. '7 is a horizontal section on the line 1-1 of Fig. 6 and lookingupwardly;

Fig. 8 is a vertical section taken through a portion of a cylinder orbarrel and illustrating another embodiment for the piston which enablesthe perforations through it to be closed or opened at will.

Fig. 9 is a view similar to Fig. 8 but in this view the section'passesthrough the piston.

Fig. 10 is a horizontal section taken on the line Iii-40 of Fig.9 andfurther illustrating details of this embodiment of the invention shownin Figs. 8 and 9.

Fig. 11 is a vertical section similar to Fig. 4 but |2-l2 of Fig. 11looking upwardly, and further illustrating details of the embodiment ofthis invention.

Fig. 13 is a view similar to Fig. 11 and illustrating another embodimentof the invention in which one of the relatively movable piston plates ismaintained yieldingly in different positions on the other plate of thepiston. This view particularly illustrates an embodiment of theinvention in which the head of the cylinder is utilized to enable theplates of the piston to be shifted relatively to each other so as toopen or close the perforations through the piston.

Fig. 14 is a horizontal cross section on the line I l-I4 of Fig. 13 andfurther illustrating details of the invention.

Fig. 15 is a horizontal cross section taken on the line l-l5 of Fig. 13and further illustrating details of the piston; and

Fig. 16 is a vertical section taken through a cylinder and illustratinganother embodiment of the invention in which the piston head is composedof an imperforate plate and a perforated plate and illustrating a lowerhead for the cylinder having an extruding orifice formed in the head.

Fig. 1'7 is a horizontal cross-section on the line II--l'l of Fig. 16.

Fig. 18 is a vertical section showing a portion of the barrel of thedevice and showing a modified construction for the piston partially insection.

Fig. 19 is a view similar to Fig. 18 and illustrating another embodimentof means for yieldingly holding the piston plates in different rotatedor oriented positions with respect to each other.

In the invention as illustrated in Fig. 1, the container is in the formof a barrel I having a removable bottom head 2 and removable upper head3. The bottom head 2 is preferably constructed so that it isquick-acting. For this purpose we prefer to employ a bayonet slot con-'struction, such as illustrated in Fig. 3, that is to say, I provide theend of the barrel with lugs 4 that are received in under-cut slots 5 inthe removable head 2. The device includes a piston 6 which includes tworelatively movable perforated parts, the perforations of which may bemoved in or out of alignment. The piston is preferably formed of twoplates 1 and 8, the latter of which is rigidly attached on the end of aninner piston rod 9 and the former of which is rigidly attached on atubular rod 10. The rods are guided out through the upper head 3 to theexterior of the device and are provided with a handle for enabling thepiston to be reciprocated, and also provided with means for holding theinner rod 9 and the outer rod 18 in different rotative positions withrespect to each other. By this means perforations It in the plate I maybe made to register with corresponding perforations 12 in the plate 8,and by rotating the plates relative to each other the perforations 12 inthe plate 8 may be drawn out of line with each other, thereby closingoff communication between the upper chamber l3 and the lower chamber Mof the barrel.

Any suitable means may be employed for ro tating the inner and outerpiston rods with respect to each other, but, asillustrated in Fig. 1, weprovide a handle 15 preferably secured on the end I6 of the inner rod 9,which projects beyond the end of the tubular rod. This handle I5 ispreferablyconstructed of bakelite or similar material and may includetwo opposite radially projecting arms II, which form a good grip for thefingers of the hand in grasping the handle. The handle and the outertube are preferably provided with means for locking them together sothat the perforations are either in alignment with each other or out ofalignment. In the present instance, we provide the tubular rod with aresilient lever Hi, the outer portion of which may be received in aradial socket 19 formed in the lower face of the handle. In addition tothis, the lower face of the handle is preferably provided with a stop20. By pulling down on the head 20 at the outer end of the spring leverI8, it can be dislodged from the socket l9 and rotated around until itstrikes the stop 20. In this position of the lever I8 the perforationsII and I2 will be out of register with each other. This gives the pistonthe effect of a solid head. After kneading the substance in thecylinder, the lever 18 can be rotated around as indicated and thesubstance within the cylinder extruded at the lower end of the cylinder,after removing the cap 2.

The handle l5 if constructed of bakelite or similar materal, ispreferably provided with a ferrule 2| which is cast at its center. Theupper extremity of the inner rod 9 is provided with screw threads 22which enables a-thumb screw 23 to be screwed down tight onto the ferruleso as to clamp the handle rigidly on the inner rod. The spring arm I8 ispreferably formed on a removable collar 24 which may be secured by a setscrew 25.

By constructing the device as described, it will be evident that it canbe readily taken apart to enable the separate pieces to be cleaned andsterilized. In doing this, the plate 8 with the inner rod 9 can bewithdrawn from the tubular rod.

In the embodiment of the invention illustrated in Figs. 4 and 5, thepiston head is composed of an upper plate 26 which is rigidly attachedto a} piston rod 21. Thispiston rod is in one piece, that is to say, inthis construction we dispensed with any tubular piston rod, such as rodin illustrated in Fig. 1. The plate 26 is countersunk into the upperside .of the lower plate 28 which is loosely mounted on the lower end ofthe piston rod. This lower plate 28 is provided with one or moreprojections or teeth 29 which extend above the upper face of the upperplate 26. By pulling the rod upwardly so as to bring the piston headagainst the inner face of the upper head 30, the projections or teeth 29can be engaged in corresponding sockets 31 formed in the inner face ofthe head 30. In this way the plate 28 can be held while the rod 21 isrotated to rotate the plate 26 and throw the perforations 32 and 33 outof alignment with each other. In other words, in this embodiment of theinvention, we provide the loose plate 28 and the head 30 with correlatedinterlocking means to enable the plate to be held fixed when thisrotation is taking place.

In order to indicate the condition or relation of the perforations onthe interior of the cylinder, we provide the side of the rod with a marksuch as the mark 34, and we provide the upper end of the boss of thehead 30 with two radial marks and 36. When the mark 34 is in alignmentwith the mark 36, the operator knows that the perforations 32 and 33 arein alignment. When the mark 34 is in alignment with the mark 35, heknows that. the perforations will be closed.

In Figs. 6 and 7 we illustrate another embodiment of the invention inwhich the piston comprises a plate 31 and a second plate 33. Theseplates have a correlated constructloni enabling them to hold themselvesin different positions. In one position the perforations will be openand in the other position they will be closed. In order to accomplishthis, we prefer to construct the plate 38 as a thin plate of resilientmaterial and we provide it with one or more rounded projections 39 onits under side which may be engaged in the upper ends of theperforations 40 of the plate 37. In this position the perforations inthe upper plate 38 are out of register with the perforations 40. In thisembodiment of the invention we may provide the same means illustrated inFig. 4 for effecting relative rotation of the plates 31 and 38. In thisconnection it should. be understood that plate 38 is loose on the pistonrod 4| but the plate 31 is rigid on this rod. The edge of the springplate 38 may be provided with one or more teeth or dogs 42 to bereceived in corresponding sockets 43 on the inner face of the cylinderhead. By pulling the piston rod out as far as possible, the dogs orteeth 42 can be engaged in the sockets 43 and the rod 4! can then berotated. This rotation dislodges the rounded projections 39 from theperforations 40 and enables them to be shifted around until they snapinto slight depressions or recesses 44 formed in the upper face of thelower plate 31. This holds the perforations of the two plates inregister with each other.

In the embodiment of the invention illustrated in Figs. 8 to 10,inclusive, the piston 45 is composed of two rigid plates 46 and 41,which are yieldingly pressed together by a resilient washer or spider48. In this construction the two plates are relatively movable on theaxis of the rod 49, as in the other constructions, but the upper plate46 of the piston is rigid with the rod. The lower plate is rotatable onan internally threaded hub 50 that is attached to the threaded andreduced lower end of the rod. Under the head of this hub 50, the spider49 is attached. This spider has a plurality of radial arms 48* which areresilient and the ends of these arms press against the lower face of theplate 41 and hold it up against the upper plate. One of the plates, forexample the lower plate 41, is provided with a radial tongue 5|, whichis received in a sectorshaped slot 52 in the opposite plate. -By thismeans the relative movement of the 'plates with respect to each other islimited. In one position the perforations in the two plates will be inalignment with each other. In the other position they will be out ofalignment with each other. With this construction, it will be evidentthat it is merely necessary to rotate the piston rod 49 to relativerotary movement or rocking movementto be accomplished. 3

If desired, the ends of the a ms 48 may be received in shallow recesses53 in the lower face of the plate 41. This prevents any possibility oftheir shifting their position so as to cover the perforations in thelower plate.

In the embodiment of the invention illustrated in Fig. 11, the piston iscomposed of an upper plate 54 and a lower plate 55, the former of whichis provided with means to enable it to cooperate with the inner face ofthe wall 56 of the cylinder to hold this plate against rotation. Theplate is rigidly secured to the lower end of the piston rod 51. Theplate 54 may be provided with a pin 58 which is received in a slot 59.This means orother means may be provided for enabling the lower plate tohave a limited rocking movement on its axis with respect to the upperplate. The upper plate is provided with one or more tongues which run'inone or more longitudinal grooves 6| formed in the cylinder wall. Withthis construction it will be evident that by rotating the rod 51 to theright or to the left the perforations in the plates can be brought intoalignment or out of alignment with each "other. 1

In the embodiment of the invention illustrated in Figs. 13 to 15,inclusive, the piston comprises a lower plate 58' and an upper plate 59,the latter of which is of thin resilient metal and preferablyconstructed so that it can be snapped over the lower end of the pistonrod 60 before the lower plate is secured in position by small machinescrew 6|. For this purpose the piston rod may be provided with aperipheral groove 62 (see Fig. 15). The plate 59' is formed with anopening 63 of slightly larger diameter than the rod 60 and atdiametrically opposite points this opening 63 has inwardly projectingedges 64 which will engage in the groove 62 when the plate 59' issnapped into position.

The upper face of the spring plate 59 is provided with one or more teeth65 which may engage in any one of a plurality of corresponding sockets66 formed on the inner face of the adjacent head 61 of the device. Onthe under side of the plate 59 one or more teeth 68 are provided, whichmay be similar to the teeth 65, and these teeth are received incorresponding sockets 69 in the upper face of the plate 58'. Thesesockets 69 are circumferentially disposed around the upper face of theplate 58' and are spaced so that in one position the perforation throughthe upper plate and lower plate will be in register with each other, andin the next position they will be out of register with each other. Withthis construction it will be evident that by rotating the rod 60'through a small angle while the teeth 85 are in the socket 66, the lowerplate 58', which is rigid with the rod, can be rotated through a slightangle, and when the teeth 68 snap into the next adjacent socket 69, theperforations in the plates will be out of register.

In Fig. 16 we illustrate a barrel with a lower head 10 having anextruding orifice 16 closed by a removable cap 11, and this view alsoillustrates another embodiment for the piston in which we employ asingle piece piston rod 18, the inner end of which carries rigidly aperforated piston plate 19 and a loose imperforate plate 80. These theother plate, said slot having an opening 83 at one end large enough toreceive the hook end of the pin. By pulling the rod 18 out as far aspossible, projections 84 can be engaged in recesses 85'on the inner faceof the head 85; the piston rod can then be rotated until the hook pinfalls into the slot; a further rotation will interlock the pistonplates. The imperforate plate 80 can then be advanced by pushing in onthe rod. This will extrude the substance from the barrel. Evidently whenthese two plates are not locked together the perforated plate can bereciprocated to knead a substance in the barrel.

The pistons are preferably constructed so that the upper and lowerplates engage the wall of the cylinder by means of a circumferential ribor bead 81 (see Fig. 1). In other words, each piston has its bodyportion of reduced diameter, as indicated at 88. This constructionenables the piston to be moved readily through the substance and at thesame time insures that the piston will fit sufliciently tight in thebarrel.

Irf the embodiment shown in Fig. 18, the cylinder wall is provided witha longitudinal groove 89 and one of the piston plates, for example theplate 93, is provided with resiliently pressed means for engaging inthis groove. This may consist of a ball 9|, held in a socket 92 andbacked up by a coil spring 93. The other plate 94 is provided with atongue 95 to run in the groove 89 to hold plate 94 when it is desired toorient the plates to open or close the perforations. The plate 90 is, ofcourse, rigid on the rod andthe plate 94 is loose.

In Fig. 19 a construction is illustrated in which one of the plates isprovided with a string pressed ball 96 for engaging in either of tworecesses 91 and 98. As illustrated in this view, the plate 99 is rigidwith the rod 30. 1

In the type of the device employing a single shaft piston rod, such asthe piston rod 69, a handle would be attachedto the rod which may, ifdesired, be similar to the handle l already described.

From the foregoing description, it is evident that in practicing ourinvention, we construct the piston of two relatively movable plates, andwith perforations which may be thrown in or out of register, and weprovide means for effecting this from the exterior of the cylinder.

In using the device, the piston is reciprocated by means of the handleI! with the perforations of the piston plates in registry with eachother. This violently forces the substance being kneaded through theperforations so that the substance passes to and fro between thechambers l3 and M of the barrel (see Fig. 1). After the substance hasbeen sufliciently kneaded, the device is operated so as to throw theperforations of the piston plates out of registry, after which the lowerhead or the cap 11 can be removed so as to permit the substance to beforced out of the barrel.

It is understood that the embodiment of the invention described hereinis only 'one of the many embodiments this invention may take, and we donot wish to be limited in the practice of the invention, nor in theclaims, to the particular embodiment set forth.

What we claim is:-

1. In a kneading and mixing apparatus, the combination of a barrel tocontain the substance to be kneaded, a piston guided to move to and froin the barrel, 2. piston rod carrying the piston, said piston having a.pair of plates with perforations therethrough capable of being movedrelatively to each other on the axis of the barrel, means associatedwith the piston plates for yieldingly holding the same in any relativeposition,

'means operatable from the exterior of the barrel for effecting therelative rotation of said plates to enable the perforations to bealigned with each other during the kneading operation, and means forforcibly reciprocating the piston while the perforations are inalignment to cause violent flow of the substance to and fro through theperforations.

2. In a kneading and mixing apparatus, the combination of a barrel tocontain the substance to be kneaded, a piston guided to and fro in thebarrel, a piston rod extending through the head of the barrel and havinga handle, said piston having a pair of plates with perforationstherethrough capable of relative rocking movement on the axis of thebarrel, means for yieldingly hold ing the plates together, said barrelhaving a head with means for engaging the adjacent piston plate to holdthe same against rotation and enable the rotation of the piston rod onits axis to bring the perforations into, or out of alignment with eachother, and means for forcibly reciprocating the piston while theperforations are in alignment to cause violent flow of the substance toand fro through the perforations.

3. .Ina kneading and mixing apparatus, the combination of a barrel tocontain the substance to be kneaded, a piston guided to and fro in thebarrel, and comprising two plates with perforations therethrough, apiston rod rigid with one of said plates, the other of said plates beingcapable of relative movement on the axis of the barrel, means forlimiting said relative movement, means on the interior of the barrel forholding the lastnamed plate against rotation in the barrel, therebyenabling rotation of the rod to bring the perforations into or out ofalignment with each other, and means carried by the rod for enabling thepiston to be forcibly reciprocated to cause the substance to passviolently to and fro through the perforations.

4. In a kneading and mixing apparatus, the combination of a barrel tocontain the substance to be kneaded, a piston guided to and fro in thebarrel and comprising a pair of plates relatively movable with respectto each other, a piston rod extending through the end of the barrel, andrigid with one of said plates, the other of said plates being ofresilient material and yieldingly engaging the other plate, said plateshaving per- 1 forations therethrough, a head on said barrel, said headand said resilient plate having correlated engaging means for. enablingthe resilient plate to be held against rotary movement by the 4 saidhead, thereby enabling the rotation of the rod to bring the perforationsinto .or out of alignment with each other.

5. In a kneading and mixing apparatus, the combination of a barrel tocontain the substance to be kneaded, a piston guided to and fro in thebarrel and comprising a pair of plates relatively movable with respectto each other, a piston rod extending through the end of the barrel, andrigid with one of said plates, the other of said plates being ofresilient material and yieldingly engaging the other plate, said plateshaving perforations therethrough, a head on said barrel, said head andsaid resilient plate having correlated engaging means for enabling theresilient plate to be held against rotary movement by the said head,thereby enabling the rotation of the rod to bring the perforations intoor out of alignment with each other, said resilient plate having aprojection thereon adjacent the other plate and operating to hold theplates yieldingly with the perforations in or out of register with eachother.

6. In a kneading and mixing apparatus, the combination of a barrel tocontain the substance to be kneaded, a piston guided to and fro in thebarrel and comprising a pair of plates with perforations therethrough, apiston rod rigid with one of said plates and passing through the end ofsaid barrel, a tubular piston=rod enveloping the first-named rod andrigid with the other of said plates, means carried by said rods forrotating the same on their axis relative to each other to bring theperforations into or out of register with each other, and means carriedby the piston rod for enabling the piston to be forcibly reciprocated tocause the substance to flow violently to and fro through theperforations.

,7. In a kneading and mixing apparatus, the

, combination of a barrel to contain the substance to be kneaded, apiston guided to and fro in the barrel and comprising a pair of plateswith a plurality of perforations therethrough, a piston rod rigid withone of said plates and passing through the end of said barrel, a tubularpiston rod enveloping the first-named rod and rigid with the other ofsaid plates, means fixed on one of said rods, and means fixed on theother of said rods, said last-named means having a correlatedconstruction enabling the same to hold the plates in a definiteposition,thereby enabling the perforations to be maintained closed or open atwill.

8. In a kneading and mixing apparatus, the

combination of a barrel to contain the substance to be kneaded, a.piston guided to and fro in the ,barrel and comprising a pair of plateswith a rod enveloping the first-named rod and rigid with s the other ofsaid plates, a handle rigidly secured to the inner rod, and means fixedon the tubular rod for enabling the same to be rotated relatively to theinner rod to maintain the perforations opened or closed.

9. Ink-a kneading and.-. .mixing apparatus; the combination of. a barrelto contain the substance to be kneaded, a piston guided to and fro inthe barrel and comprising a pair of plates with a plurality ofperforations therethrough, a piston rod rigid with one of said platesand passing through the end of said barrel, a tubular piston rodenveloping the first-named rod and rigid with the other of said plates,a handle rigidly secured to the inner rod, and means fixed on thetubular rod for enabling the same to be rotated relatively to the innerrod to maintain the perforations opened or closed, said last-named meansand said handle having interlocking means for maintaining theperforations in a definite ,relation to each other.

10. In a kneading and mixing apparatus,.the combination of a barrel tocontain the substance to be kneaded, a piston guided to and fro in thebarrel and comprising a pair of plates with a plurality of perforationstherethrough, a piston rod rigid witl one of said plates and passingthrough the end of said barrel, a tubuiar piston rod enveloping thefirst-named rod ans. rigid with the other of said plates, said inner rodprojecting beyond the end of the tubular rod, a handle rigidly securedto the end of the inner rod beyond the tubular rod, a lever carried bythe tubular rod adjacent the handle and enabling the tubular rod to berotated relative to the inner rod to control the relative position ofthe perforations.

11. In a kneading and mixing apparatus, the

combination of a barrel to contain the substance to be kneaded, a pistonguided to and fro in the barrel and comprising a pair of plates with aplurality of perforations therethrough, a piston rod rigid with one ofsaid plates and passing through the end of said barrel, a tubular pistonrod enveloping'the first-named rod and rigid with the other of saidplates, said inner rod projecting beyond the end of the tubular 110d, ahandle rigidly secured to the end of the inner rod beyond the tubularrod, a lever carried by the tubular rod adjacent the handle and enablingthe tubular rod to be rotated relative to the inner rod to control therelative position of the perforations, and correlated interlocking meansbetween the lever and the handle for maintaining the perforations in orout of register with each other.

12. In a kneading and mixing apparatus, the combination of a barrel tocontainthe substance to be kneaded, a head on the barrel, 9, pistonguided to and fro in-the barrel and comprising a pair of plates withperforationstherethrough, a piston rod rigid with one of said plates,the other of said plates mounted for rocking movement on the axis .ofthe rod, ahead on the barrel,

said head and the loose plate having correlated.

interlocking means for enabling the loose plate to be held againstrotation while the rod and the other plate are rotated to bring theperforationsinto or out of alignment with each other.v

13. In a kneading and mixing device, the combination of a cylinder, apiston rod movable'therein, a piston plate rigidly mounted on the end ofsaid rod, a second piston plate loosely mounted on the rod adjacent thefirst-named plate, said plates having perforations which may registertogether, and yielding means carried by one of said plates for engagingthe other plate, the-said other plate having means for engaging theyielding means to enable said plates to be held in different orientedpositions with respect to each other.

14. In a kneading and mixing apparatus, the combination of a barrel, atubular piston rod guided through the same, an inner rod mounted withinthe tubular rod, a handle carried by one of said rods for reciprocatingthe saine, a piston plate carried by the inner rod within-thebarrel, apiston plate carried by the tubular rod within the barrel lying adjacentto the first-named piston plate, said piston plates having a pluralityof perforations therethrough which may align, means for effecting arelative rotation of the inner rod and the tubular rod to maintain theperforations at will in register or out of register with each other, andmeans on .the rods for forcibly reciprocating the piston plates to causeviolent movement of the substance to and fro through the perforationswhen in alignment.

. WALTER J. Gm ROSSEM.

LAURENCE nnanmson.

